The Perseid meteor shower is caused
by debris from Comet Swift-Tuttle.
Every 133 years the huge comet
swings through the inner solar
system and leaves behind a trail of
dust and gravel. When Earth
passes through the debris, specks
of comet-stuff hit the atmosphere
at 140,000 mph and disintegrate in
flashes of light.
The Perseids are a popular attraction in the night sky in August each year.